I think the answer is number3
Answer:
Marine debris can be harmful to coral reefs. Recycle your trash at home and on the go (especially plastic), and remember the three R's (reduce, reuse, and recycle). When disposing of trash, do it properly in bins, to avoid trash being blown or washed away into waterways and oceans.
Explanation:
The Khmer's came from Cambodia.
It traps the heat in instead of letting it out into space. For this reason CO2 is a greenhouse gas.
